Dietary resveratrol altered the microbial composition and restored microbial community diversity in colitic mice, which was associated with the suppression of colitis in the mice.

BACKGROUND:Organophosphate and carbamate pesticide residues in food and the environment pose a great threat to human health and have made the easy and rapid detection of these pesticide residues an important task. Discovering new enzyme sources from plants can help reduce the cost of large-scale applications of rapid pesticide detection via enzyme inhibition.RESULTS:Plant esterase from kidney beans was purified. Kidney bean esterase is identified as a carboxylesterase by substrate and inhibitor specificity tests and mass spectrometry identification. The kidney bean esterase demonstrates optimal catalytic activity at 40 °C, pH 6.5 and an enzyme concentration of 0.30 µg mL-1 . The kidney bean esterase can be inhibited by organophosphate and carbamate pesticides, which can be substituted for acetylcholinesterase. The limit of detection of the purified kidney bean esterase was two- to 20-fold higher than that of the crude one. The method detection limit meets the detection requirement for the maximum residue limits (MRL) in actual samples.CONCLUSION:The findings of the present study provide a new source of enzymes for pesticides detection by enzyme inhibition. © 2018 Society of Chemical Industry.

Specific Lactobacillus reuteri is autochthonous Lactobacillus species in humans with potential application in food production as a probiotic. The difference in colonizing Peyer's patches (PP) might decide their health-promoting properties. We aimed to investigate the difference between PP- and lumen-specific L. reuteri on antimicrobial peptide expression in this study. L. reuteri strains were isolated from PP and the lumen of C57BL/6J mice, which were used to treat mice. PP-specific L. reuteri cells stimulate RegIIIγ mRNA expression of the crypt epithelial sample. PP-specific L. reuteri induces accumulation of extracellular DNA (eDNA) in the bottom of crypts. eDNA was extracted from the small-intestinal mucus, the yield of which was significantly increased after the PP-specific L. reuteri treatment. And it increased cytokine production in RAW264.7 murine macrophages. PP-specific L. reuteri significantly increased the relative abundance of Bacteroidetes-, Lactobacillus-, and Proteobacteria-derived eDNA. However, the levels of Strentrophomonas-derived eDNA decreased. These results provide a rationale for the screening of human derived L. reuteri with an immune-modulatory property.

Accumulating evidence indicated that gut microbiota play important roles in the pathogenesis of colitis, and microbiota composition could be modulated by dietary components. Therefore, ameliorating colitis‐associated bacterial dysbiosis by dietary components may be a unique strategy to improve gut health. Herein, we determined the effects of resveratrol on gut microbiota and their implication in anti‐colonic inflammation in mice with colitis induced by dextran sodium sulfate (DSS). Our results showed that DSS treatment dramatically disturbed the composition of gut microbiota in mice, which was associated with elevated colonic inflammation. Dietary treatment with resveratrol partially attenuated the gut microbiota dysbiosis induced by DSS, for example, resveratrol effectively reduced the abundance of bacteria from Verrucomicrobia and Proteobacteria phyla, decreased the abundance of Sutterella and Bilophila genera, and increased the abundance of Bifidobacterium and Lactobacillus genera in DSS‐treated mice. Alpha and beta‐diversity analysis showed that DSS treatment reduced the microbial diversity and shifted the microbial community structure in comparison with the negative control (healthy) mice, while resveratrol ameliorated the aforementioned alteration and restored the diversity of the gut microbiota in DSS‐treated mice. Furthermore, resveratrol alleviated the symptoms of colitis and decreased the expression levels of pro‐inflammatory cytokines such as IL‐10, IL‐2, GM‐CSF, IL‐1β, IL‐6 and TNF‐α, in the colon of DSS‐treated mice. Overall, our data demonstrated that resveratrol partially reversed bacterial dysbiosis in DSS‐treated mice, which may play an important role in its anti‐colitis effect.Support or Funding InformationThis study was partially supported by fund from USDA

The gut microbiota play critical roles in human health, and diet can modulate the compositions of the gut microbiota, which in turn may contribute to altered health outcomes such as changes in the risks of chronic diseases. Limonin is one of the major bioactive compounds found in citrus fruits and have been reported to possess various beneficial health effects. This study was aimed to determine the effects of dietary limonin on the gut microbiota. Mice were fed limonin in the diet (0.05% w/w) for 5 weeks, and the microbiota were isolated for composition analysis. Terminal restriction fragment length polymorphism (T‐RFLP) patterns and Misequencing analysis were used to profile gut microbiota in the cecum, colon and feces of the mice. The results showed that compared to the control mice, treatment of limonin did not cause significant change on the diversity of the cecal microbiota, while significant changes were observed in the diversity of colonic microbiota after limonin treatment. In the colon, abundance of colonic Enterobacteriaceae was decreased by 10‐fold, while the abundance of Bifidobacteria and Lactobacillus was increased significantly in the mice treated with limonin (p<0.001). Moreover, the abundance of colonic Clostridiales was reduced to one third of that of the control mice by the administration of limonin. Overall, our study provide the first line of evidence that dietary limonin could alter gut microbiota, which warrants further investigation to determine its implication in human health.Support or Funding InformationThis study was partially supported by fund form USDA.